Flexible, stretchable coiled-sheet stent

Abstract

A coiled-sheet stent includes a tubular body having a longitudinal axis and a circumference, and a plurality of cylindrical bands formed in the tubular body, each band having a zig-zag pattern including a series of sequential diagonal elements connected to one another and extending about the circumference. A plurality of longitudinal connectors extend between and connect adjacent bands. The diagonal elements have an arcuate shape, all diagonal elements in each band being oriented in either a clockwise or counter-clockwise direction about the circumference. The tubular body is expandable between contracted and enlarged conditions, and the zig-zag pattern is expandable between unstretched and unstretched conditions, the zig-zag pattern being biased towards the stretched condition above a transition temperature, thereby at least partially defining the enlarged condition. A multi-cellular stent structure is also provided that includes a plurality of bat shaped cells formed in a tubular body, each cell defining a head region, a tail region and opposing curved wing regions, and a plurality of connectors extending between and connecting adjacent cells. The head and tail regions of adjacent cells are directly connected to one another, and connectors extend between adjacent wing regions of adjacent cells.

1. A stent, comprising:
 a generally tubular body having a longitudinal axis and a circumference, and having a size adapted for introduction into a body lumen, wherein said tubular body comprises a coiled-sheet, 
 said tubular body consisting essentially of a series of generally non-sinusoidal cylindrical bands and a plurality of straight, generally non-sinusoidal, longitudinal connectors extending between and connecting adjacent cylindrical bands, each longitudinal connector having a length, each cylindrical band comprising a series of diagonal elements connected to one another and extending about the circumference, wherein each diagonal element comprises first and second generally straight portions having first and second ends, the second ends being connected together in a curved portion, the first ends being connected to preceding and succeeding diagonal elements, and wherein each longitudinal connector consists of a straight segment that extends between longitudinally separated curved portions, and 
 wherein all of the diagonal elements in all of the cylindrical bands comprising the tubular body are oriented in a clockwise direction about the circumference. 
 
   
   
     2. The stent of  claim 1 , wherein the tubular body is expandable between a contracted condition for facilitating introduction into a body lumen and an enlarged condition for engaging a wall of a body lumen. 
   
   
     3. The stent of  claim 2 , wherein the tubular body is biased toward the enlarged condition. 
   
   
     4. The stent of  claim 2 , wherein the cylindrical bands are expandable between an unstretched condition and a stretched condition, the cylindrical bands being biased toward the stretched condition above a transition temperature that is substantially below body temperature, thereby at least partially defining the enlarged condition. 
   
   
     5. The stent of  claim 4 , wherein ends of adjacent diagonal elements are arranged further away from one another about the circumference in the stretched condition than in the unstretched condition. 
   
   
     6. The stent of  claim 1 , wherein the longitudinal connectors have a longitudinal dimension that is substantially smaller than a longitudinal dimension of the diagonal elements. 
   
   
     7. The stent of  claim 1 , wherein the diagonal elements of each cylindrical band are out of phase with any adjacent cylindrical band. 
   
   
     8. The stent of  claim 1 , wherein each longitudinal connector extends substantially parallel to the longitudinal axis. 
   
   
     9. A stent, comprising:
 a generally tubular body having a longitudinal axis and a circumference, and having a size adapted for introduction into a body lumen, wherein the tubular body comprises a coiled-sheet, 
 said tubular body consisting of a plurality of cylindrical bands, each cylindrical band consisting of a sequence of bat-shaped cells, each of said generally bat-shaped cells formed from a plurality of generally non-sinusoidal cylindrical bands and a plurality of straight, generally non-sinusoidal, longitudinal connectors extending between and connecting adjacent cylindrical bands in the tubular body, each longitudinal connector having a length, each cell defining a head region, a tail region and opposing curved wing regions, the head region of each cell being connected to the connected to the tail region of an adjacent cell, wherein each head region is defined by a longitudinal connector, and wherein each tail region is defined by a longitudinal connector, 
 wherein the wing regions are defined by first and second arcuate members, the first and second arcuate members comprising a pair of generally straight portions connected to one another by a curved portion, 
 wherein the curved portion defines an apex of the curved wing regions, the apices all pointing substantially in a single direction; and 
 wherein each longitudinal connector consists of a straight segment. 
 
   
   
     10. The stent of  claim 9  wherein the head and tail regions are aligned about the circumference, and the wing regions have a generally “V” shape extending longitudinally away from the head and tail regions. 
   
   
     11. The stent of  claim 10 , wherein the cells are arranged sequentially about the circumference, thereby defining a cylindrical band. 
   
   
     12. The stent of  claim 9 , wherein the longitudinal connector defining each head region extends between the first arcuate members of the opposing wing regions of the respective cell, and longitudinal connector defining each tail region extends between the second arcuate members of the opposing wing regions of the respective cell. 
   
   
     13. The stent of  claim 12 , wherein one of the generally straight portions of each of the first and second arcuate members is substantially shorter than the other generally straight portion of the respective arcuate member. 
   
   
     14. The stent of  claim 12 , wherein the longitudinal connector defining the tail region also defines the head region of an adjacent cell. 
   
   
     15. The stent of  claim 9 , wherein the plurality of connectors comprise a longitudinal connector extending between a wing region of a first cell and a wing region of an adjacent cell. 
   
   
     16. The stent of  claim 9 , wherein the tubular body is expandable between a contracted condition for facilitating introduction into a body lumen and an enlarged condition for engaging a wall of a body lumen. 
   
   
     17. The stent of  claim 16 , wherein the tubular body is biased towards the enlarged condition.